Covulcanizable mixes comprising diene polymers or copolymers and low unsaturation terpolymers

ABSTRACT

A terpolymer-diene composition that is readily curable with conventional vulcanizing agents is provided by preparing a mixture of diene polymer or copolymer with an olefinic terpolymer which includes at least one GROUP DIRECTLY BOUND TO TWO CARBON ATOMS, EACH OF WHICH IS CHARACTERIZED BY ETHYLENIC UNSATURATION, WHEREIN R1 is a hydrocarbon radical.

United States Patent Corradini et a1.

[54] COVULCANIZABLE MIXES COMPRISING DIENE POLYMERS OR COPOLYMERS AND LOW UNSATURATION TERPOLYMERS [72] Inventors: Giorgio Corradini; Giuseppe Ghetti; Sebastiano Cesca; Arnaldo Roggero, all of San Donato Milanese, Italy [73] Assignee: Snam Progettic S.p.A., Milan, Italy [22] Filed: Apr. 23, 1970 [21] Appl. No.: 31,411

[30] Foreign Application Priority Data Apr. 23, 1969 Italy ..15874 A/69 [52] [1.8. CI ..260/5, 260/8078, 260/889 [51] Int. Cl. ..C08f 17/00 [58] Field of Search ..260/5, 888, 889, 80.78, 88.20

[56] References Cited UNITED STATES PATENTS 3,492,370 l/l970 Wirth ..260/889 1 June 6,1972

Primary ExaminerJohn C. Bleutge Attorney-Ralph M. Watson [57] ABSTRACT A terpolymer-diene composition that is readily curable with conventional vulcanizing agents is provided by preparing a mixture of diene polymer or copolymer with an olefinic terpolymer which includes at least one group directly bound to two carbon atoms, each of which is characterized by ethylenic unsaturation, wherein R, is a hydrocarbon radical.

4 Claims, No Drawings COVULCANIZABLE MIXESCOMPRISING DIENE POLYMERS OR COPOLYMERS AND LOW UNSATURATION 'I'ERPOLYMERS The present invention refers to vulcanizable mixes comprising diene polymers or eopolymers and low unsaturation terpolymers.

it is known that an important obstacle to introducing into the market terpolymers consisting of alpha-olefin: and

polyenes resides in the fact that said terpolymers cannot be The following not limitative examples illustrate the invencured when mixed with such conventional diene polymers as synthetic polyisoprene, natural rubber, polybutadiene, acrylonitrile-butadiene and butadiene-styrene copolymers in the presence of the conventional accelerating and curing agents.

The impossibility of producing mixes consisting of olefinic terpolymers and diene polymers or copolymers does not allow one to obtain articles presenting at the same time the good features of the olefinic terpolymers, for instance the high aging resistance and the low cost of the diene polymers and copolymers.

We have now found a new class of olefinic terpolymers which may form mixes which are covulcanizable with high unsaturation diene polymers andcopolymers.

The tel-polymers which can be covulcanizcd with the diene polymers and copolymcrs are the ones consisting of ethylene, propylene and a polyene having at least it Hi Jurgroup directly bound to two carbon atoms each one of them taking part in an ethylenic unsaturation, wherein R is a hydrocarbon radical.

The polyenes which can be advantageously employed to form the terpolymers according to the present invention are the ones presenting besides a double bond which is engaged in the polymer fonnation, a residue of the following type:

a, R, 11 R, 'R.

wherein R,, R,, R,, R, and R. may be hydrogen or hydrocarbon radicals having one to five carbon atoms, furthermore the radicals R, to R; may form two by two one or more divalent radicals in order to introduce within the above residue one or more rings having four to seven carbon atoms. The above structure may also consist of a polyene ring when the two external carbon atoms are linked together.

Examples of teipolymers advantageously employed according to the invention are the ones claimed by the applicant .in the copending application for patents 11. 20868 A168, which corresponds to US. application Ser. No. 855,771, filed Sept. 5, l969 25239 A/68 which corresponds to US. application Ser. No. 886,390, filed Dec. 18, 1969 and 25242 A168 now Italian Pat. No. 851,694 and other copending applications.

The mixture of olefinic terpolymers and diene polymers or tion, however, they are not to be intended to restrict its scope.

EXAMPLE 1 a. A terpolymer consisting of ethylene, propylene. dehydnodicyclopentadiene was prepared according to the following procedure. in a 500 cm tubular reactor, provided with mechanical stirrer, thennometric sheath and a jacket for the thermostatic fluid 1,000 cm of n-hexane are introduced under inert gaseous atmosphere. in the same time a propylene-ethylene mixture having a molar ratio 2 to l was introduced in the bottom of the reactor at a flow of l200'Nl/h; inorder to improve the attainment of the saturation equilibrium the solvent was stirred during the gas introduction, while keeping its temperature at -20 C. by circulating through the reactor jacekt a freen'ng mixture controlled with a cryostat. Afier 20 minutes of bubbling of the monomers mixture, the equilibrium conditions were presumably reached. Thereupon 2.4mmole/l of(C,H,),AlCl, l.2mmoles/l of anisole and l.5m- '5 moles/l of dehydrodicyclopentadiene (or 5,2,1 ,0 7a, 3adeeatriene-Zi,5,7a) were introduced into the reactor, while the stream of gaseous monomers kept flowing the polymerization reaction was started by adding 0.4 mmoles/l of VCL.

The polymerization continued for 4 minutes; each minute 2mmoles/l of dehydrodicyclopentadiene were added.

The reaction was stopped by introducing l cm, of n-butanol into the reactor. 5

The reaction solution was washed with HCl acidulous water,. then with H,O until neutralization, thereupon it was coagu-.

lated by slow addition of an excess of acetone, to which an aminic antioxiden A0 has been added.

Afier drying at a reduced pressure for 15 hours at 50 C., an elastomeric mass was obtained having the aspect of noncured rubber, in an amount of l8.3 g.

At the Xrays analysis said mass was completely amorphous revealing a QH. weight content of 61 percent while the intrinsic viscosity in toluene at 30 C. was 2.62 dl/g.

The dehydrodicyclopentadiene determination by iodometric titration gave 2.47 percent by weight.

b. The sample obtained in a was mixed on an open mill at room temperature with SBR 1,500 and conventional curing agents according to the following recipe: EPT 75, SBR 1,500 25, HAP 50, Circosol 4,240 5, Zinc oxide 5, stearic acid 1, mercaptobenzothiasole 0.5, tetramethyltriuran disulfide 1.5, sulfur L5.

The obtained mixture was vulcanized in a press at 145 C.

for 40 minutes.

in Table l are reported the results of the tensile stress tests copolymers may present a wide range of properties of the two 50 carried out on dumbell test pieces obtained from the obtained TABLE I.-COVULCANIZATlON OF EFT/5BR /25 Extraction Termonomer Tcrrnonomer (percent (g tol. M 100% M .0071, C.lt. AJL, i. set, ()llCh,

ea (type) (molrlkgJ by welitht) C. (k n/cm!) (kg/rm!) (kw/em!) perm-ht percent percent A 0.190 m a 6'2 46 m1 no am in 7 l l, b hr-xndltun. l). (70 Ni 1. 7H 3H 36 lilo llr 3H (1 0.470 Oil L 0 6" 66 2b" '60 3H 7 EXAMFLM a. A terpolymer was prepared comprising ethylenepropylene-2(or 3)-allyldicyclopentadiene according to the usual procedure.

n.eptane 1000 cm V( Acetylacetonate), 0.7 mmole (C,H,) AlCl 5.6 mmoles C;,H,/C,H 2.0 (moles in gaseous phase) temperature C.

reaction time minutes After drying 16.4 g. of an elastomer completely amorphous at X-rays analysis were obtained and presented the charac teristics shown in Table IV. I

b. The sample according to paragraph a of the present example was mixed at room temperature with SBR 1,500 and conventional vulcanization agents, on open mill. The following recipe was employed: EPT 75 SBR 1,500 25, HAF 50,-circosol 4,240 5, Zn oxide 5, stearic acid 1', mercap tobenzothiasole 0.5, tetrarnethylthiuramdisulfide 1.5, sulfur 1.5.

The mix was vulcanized at 145 C. for 40 minutes. In Table IV the data of the tensile stress tests carried out on double test piece obtained from the moulded plates are reported, as well as the extraction percentage with CHCl (48 h. in Soxhlet) of the same plates.

monomer is represented by the following formula:

3. A vulcanizable mix claimed claim 1 wherein said termonomer is represented by thefollowing formula:

TABLE IV.COVULCANIZ ATION 0F EP'I AND SBR 76/25 Termon- CzHi omer (Percent Extrac- (mole/ by [1 tol. Ml00%, M20075, A.R., P. sat, tion, Test Tel-monomer (type) I kg.) weight) C. kgJcm. lrgJctn. kgJcm. percent percent percent CH;CH=CH,

What is claimed is: 4. A vulcanizable mix as claimed in claim 1 wherein said termonomer is represented by the following formula:

3-0 Hz-C H=C H:

Po-ww UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,668,156 mud Jun 5, 1972 Inventor) Giorgia Corradini, Giuseppe Ghetti, et a1 It is certified that ertor appeara in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

line 37, "1 cm should read 1 cm Column 3, line 4, "(EPAM)" should read (EPDM) Column 5, line 28., change "ChCl to read CHC Column 4, Table II; in the sub-heading(lastoccurrence) after "M 100" insert 7.

Signed and sealed this 19th day of March 19%..

(SEAL) Attest:

EDWARD M.FLETCHER,'JR. c. MARSHALL DANN Attesting Officer Commissioner of Patents 

2. A vulcanizable mix as claimed in claim 1 wherein said termonomer is represented by the following formula:
 3. A vulcanizable mix as claimed in claim 1 wherein said termonomer is represented by the following formula:
 4. A vulcanizable mix as claimed in claim 1 wherein said termonomer is represented by the following formula: 